The present invention relates to an excavator tool quick attachment device and more particularly to a safety mechanism for an excavator tool quick attachment device.
Pneumatic/hydraulic latches on quick attachment devices are well known and are generally mounted on a tool engaging portion which has two hooks, one of which is on each end of the device. The excavator operator locates one of the hooks around the first pin of the tool and raises a dipper arm of the excavator. The rams of the dipper arm are manipulated until the second hook is located adjacent the second pin of the tool and a pneumatic/hydraulic latch comprising a hydraulic/pneumatic piston connected between the attachment device and the latch is actuated to lock the second pin of the tool onto the quick attachment device.
The problem with this latch is that failure of the hydraulic/pneumatic cylinder could result in the latch opening and allowing the tool such as a bucket to become separated from the quick attachment device with potentially disastrous consequences for anyone in the vicinity. A number of safety pins and other safety mechanisms have been developed but most of these require to be inserted manually. Further secondary safety systems utilising hydraulic systems have also been developed which add extra system maintenance and expense.
It is an object of the present invention to overcome the need for manually operable safety pins or complex hydraulic systems, both of which are used to prevent unintended release of the tool from the quick attachment device.